We tested 30 Sheffield plumbers’ websites on a phone

The result

On 27 October 2026 I tested 30 independent plumbing and heating websites in Sheffield and South Yorkshire on a simulated phone with a slow connection. 28 of them took longer than 2.5 seconds to show their main content. Google treats 2.5 seconds or less as good, so 2 sites passed.

The median was 4.8 seconds. The middle half of sites sat between 3.6 and 7.3 seconds, and 9 took longer than 6 seconds. The quickest showed its main content in 2.1 seconds, the slowest in 11.7.

No business is named in this guide. The aim is to describe the trade, not to point at anyone.

What this means for a plumber

Someone with a leak or no hot water is usually on their phone, often on mobile data. They want to see who you are and ring you. A page that takes five seconds to show anything useful is a poor start, and other plumbers are one search away.

A slow result in a lab test does not mean customers left. It means there is a known, fixable delay. I did not measure real visitors, so I cannot say how many calls a slow page cost.

Heavy pages were the slow ones

The median homepage weighed 2.2 MB and made 64 requests. 20 of the 30 were over 1 MB and 7 were over 3 MB. The 10 sites at or under 1 MB had a median of 3.6 seconds. The 20 heavier ones had a median of 5.3.

In the first test run Lighthouse flagged image delivery, meaning oversized or poorly compressed photos, on 26 of the 30 sites. Layout shift, the page jumping as it loads, was within Google’s limit on 28 of 30.

Scores move by about 10 points between identical runs, so do not read much into two sites a few points apart.

Phone calls, proof and housekeeping

27 of 30 homepages had a tap-to-call link, 25 had a contact or quote form and 10 offered WhatsApp. All 30 mentioned Gas Safe, while only 1 mentioned WaterSafe.

22 showed or linked reviews and 18 linked a Google Maps or Business Profile page. Half (15) had business-type structured data, and 5 of those specifically said “Plumber”. 3 showed a copyright year from 2024 or earlier, 8 showed no year, and 1 set it by script.

Five takeaways for a plumber

1. Shrink the photos. Page weight and speed moved together. Ask whoever built your site to resize and compress images, and aim for a homepage under 1 MB.
2. Check the tap-to-call button. 3 of 30 homepages had none. Make the number dial with one tap and keep it visible without scrolling.
3. Add WhatsApp if you are happy to use it. Only 10 of 30 offered it, and a photo of the boiler or the leak often says more than a description.
4. Show your proof where people look: reviews, a Google Maps link and your registrations. WaterSafe was mentioned once, so if you hold it, say so.
5. Do the small jobs: business-type structured data, a current copyright year, and text with enough contrast against its background. A good developer can do these in an afternoon.

How I ran the test

I found candidates through web searches for plumbing, heating and boiler firms in Sheffield, Rotherham, Barnsley, Doncaster and nearby towns. I left out national chains, lead-generation directories, Facebook-only businesses and sites that would not load. The 30 are the first usable independent firms the searches turned up.

Each homepage was tested with Lighthouse 13.5.0 using its mobile preset and default throttling, twice, and I kept the better clean run. Other checks read the page’s HTML directly. Run to run, scores varied by up to 24 points, so treat single scores as plus or minus 10.

What this does not show

• 30 sites found by search is a small sample. It probably leans towards firms that already care a little about their website.
• It covers homepages only, on one day, from one location. Lab data is not what real customers experience, and I collected no real-visitor figures.
• Checks that read raw HTML can miss items loaded by script, so counts for widgets, chat buttons and some forms are lower bounds.
• Gas Safe and WaterSafe were counted as mentions on the page. I did not check the registers.
• The groups of site builders were too small to rank any of them.

Check your own site for free

1. Open Google’s PageSpeed Insights and paste your homepage address.
2. Read the Mobile tab, and look at the Largest Contentful Paint figure. Under 2.5 seconds is good.
3. Open the list of opportunities and look for images. Send that list to whoever looks after your site.

Every site is a number, with no names or addresses. Download the anonymised data (CSV)

Related: PageSpeed Insights, Websites for plumbers, Free website check, Website redesign